Add .env file to contain config variables

The .env should look like this:
export QUIZ_DEBUG="True"
export QUIZ_SECRET_KEY="Secret key goes here"
something you already know :)
make questions slightly more explicit with slicing and list comprehension
dead code removal
Define exception to catch more narrowly
dead code removal
DRY up submission code
clean up question unpacking
Merge pull request #1 from akaptur/code-review

Code review!